Artificial light pollution increases the sensitivity of tropical zooplankton to extreme warming

Abstract

Abstract Artificial light pollution and climate change are two important threats to the coastal ecosystems worldwide. However, the potential interaction of artificial light and extreme warming on coastal species is unknown. To address this issue, we exposed a tropical copepod Pseudodiaptomus incisus to one of twelve combinations of four photoperiods (0L:24D, 12L:12D, 18L:6D and 24L:0D — light: dark cycle) and three temperatures (26, 30 and 34 °C). We quantified five key productivity parameters, including development time, body size of all 12 development stages, clutch size, hatching success and nauplii production. P. incisus had a larger body size and clutch size and higher nauplii production at the photoperiod of 12L:12D and 18L:6D than in continuous lighting condition (24L:0D). Copepods developed faster but showed smaller body size, clutch size, hatching success and nauplii production at 34 °C than at 30 and 26 °C. Importantly, continuous lighting resulted in stronger reductions in body size, clutch size, hatching success and nauplii production at 34 °C. Our results suggest that continuous lighting may increase the vulnerability of coastal zooplankton to climate change with ecological consequences.